Fix PAL PSX crashes due to insufficient framebuffer

Some PAL games (including Silent Hill) crash because they use a larger framebuffer than 700x480. This fixes that; it also changes the FPS and region reported for PAL games (though it seems RA uses audio to sync anyway).

PAL still has some cropping and letterboxing/windowboxing related problems. These were often issues on actual PAL TVs too, but it should be possible to correct the overscan cropping currently used- I'll work on it sometime. These changes do not affect non-psx mednafen modules.